I don't drive and end up shopping at the grocery store across the street. It is not a cheap store.
I look at the weekly flyer and make a list.
I buy some food at the local drug store (check flyer)
I do go to a small fruit market up the street and they often sell veg and fruits cheaply.
I go to the farmers market when I can. But I live in a major city, the farmers markets focus on organic and are more expensive then the big chain non organic stores. But it is cheaper then going to the organic stores. I eat local and organic as much as possible.
I do not waste food. I use food in soups etc.
Right now cabbage, carrots and onions are staples. Apples too.